1. Field of the Invention
The invention relates to a coal fired power generation plant operating on the basis of a high temperature steam process.
2. Brief Description of the Related Art
The generation of electrical energy by means of coal fired power generation plants is being constantly improved in terms of environmental friendliness of coal combustion and an increase in the efficiencies of the plants. In the report “Dampfturbinen auf Rekordkurs” (Steam turbines set for a record) in the journal Energie, Edition 47, No. 1-2, January/February 1995, there is a description of coal fired power generation plants with high temperature steam turbines that are achieving increased efficiencies. The turbines can be operated at fresh steam temperatures of up to 580° C. and at fresh steam pressures of up to 270 bar through the use of new high temperature resistant materials such as ten percent chrome steel. The high temperature steam process mentioned is also suitable for the application of carburation and the combination of gas and steam power generation plants using pressurized fluidized bed combustion.
WO 02/084080 describes a steam power generation plant with increased efficiency having a retrofitted high temperature turbo train arranged on a separate rotor, in which the separate rotor is either coupled to the existing rotor or uncoupled from it. Components of steel or nickel-based materials are used for the high temperature turbo train, allowing the turbo train to be operated with fresh steam of up to 720° C. and up to 375 bar. The increased fresh steam temperature in the boiler is achieved, for example, by modifying the superheater or connecting in series a further superheater.
In “Modern Power Systems”, April 1997, p. 33 et sqq., a description is given of a coal fired power generation plant which has a boiler with pressurized fluidized bed combustion (“PFBC”). This boiler supplies fresh steam for a high pressure steam turbine and reheated steam for an intermediate pressure steam turbine, as well as high pressure exhaust gas for a gas turbine.